(a) Field of the Invention
The present invention relates generally to a spray gun structure. More particularly, the present invention is directed to a spray gun that may be used to eject water only or a mixture of water and detergent.
(b) Description of the Prior Art
With conventional spray gun structures, as that shown in FIG. 1, the spray gun essentially comprises a gun body 2 with an interior defining a water passage 22, a handle 21 at a bottom portion of the gun body 2, a valve rod 3 extending from a rear end of a top portion of the gun body 2 into the water passage at the top portion of the gun body 2, a lever 4 pivotally connected to a rear end of the valve rod 3 so that the valve rod 3 may be retractably controlled to allow or cut off flow of water in the interior of the gun body 2, and a nozzle 5 (a conventional structure and will not be described in detail herein) that may be adjusted to vary the pattern of sprayed water. After assembly of these components, the lever 4 may control the stroke of the valve rod 3 due to linking-up movement, thereby achieving control of the amount of ejected water when water passes from the water passage 22 inside the handle 21 at the bottom portion of the gun body 2 to the interior of the gun body 2 and out through the nozzle 5. The structure and operation of such conventional spray guns are not described in further detail herein as they are well known in the art.
Such conventional spray guns are generally used in gardening, car washing and household cleaning. In car washing, the user usually ejects liquid detergent on the car to clean the car before washing away the detergent and dirt with clean water. Since the conventional spray gun can only eject water and control the amount of ejected water, the user has to use a separate means to spray detergent onto the car.
Reference is made to FIGS. 2, 3, and 4, which show a spray gun structure directed to providing the dual functions of ejecting water only or a mixture of detergent and water, as disclosed in the inventor's co-pending application. That spray gun structure is essentially comprised of a handle 8, a lever 9 provided at a bottom portion of the handle 8 for control of water intake, a connecting body 10 located at a top portion of the handle 8 and extending forwardly, the connecting body 10 having a water channel 101 a rear end of which is connected to a water conduit 91 inside the lever 9, a gun body 11 connected to a front portion of the connecting body 10, and a nozzle 12 pivotally connected to a rear end of the gun body 11 directly or by extension (not discussed herein as it is a conventional structure). The lever 9 is comprised of the water conduit 91, a control valve 92, a control lever 93, and a press plate 94. The water conduit 91 has a top end with an outer periphery insertably disposed in a rear end of the water channel 101 inside the connecting body 10, a water passage 911 which has a relatively small internal diameter at an upper section and a relatively large internal diameter at a bottom section, and a guide groove 912 disposed at one side of the bottom section thereof. The control valve 92 has a sealed top end and is provided with a water passage internally. The control valve controls the connection between its water passage and the water conduit 91. An annular guide rim 921 is provided at a middle section of an outer periphery thereof, for matching the guide groove 912 at the bottom portion of the water conduit 91. Gaskets 913 are respectively disposed at the top end of the control valve 92 and the periphery of the annular guide rim 921. A water outlet 914 is disposed between the annular guide rim 921 and the top end of the control valve 92. The control lever 93 has one end insertable into the annular guide rim 921 of the control valve 92 via the guide groove 912 of the water conduit 91 so that it may control the slidable displacement of the control valve 92. The press plate 94 may operate the control lever 93 to control the control valve to slidably displace. Such an arrangement controls the water current entering from the bottom end of the lever 9 into the water channel 101 inside the connecting body 10. But since such control of water current is well known in the art, it will not be discussed in detail herein. The present invention is characterized in that a detergent receiving tank 13 is mounted onto the periphery of the assembly of the connecting body 10 and the gun body 11. The detergent receiving tank 13 is provided with a filler hole 131 at an annular periphery thereof. The filler hole 131 has an internal taper 1311 at a top end thereof. A detergent release hole 102 is disposed at a rear end of the water channel 101 of the connecting body 10 such that a rear end of the release hole 102 may extend into the detergent receiving tank 13. The release hole 102 is further connecting to a detergent suction straw 14 that has a suction port 142 having a load 141 at a rear end thereof. There is further provided a control device comprising a cap 151 and a leakage-proof block 152. The cap 151 is fitted onto the filler hole 131. The cap 151 comprises an air vent 1511 centrally disposed at a top surface thereof, the top surface extending inwardly to form a positioning flange 1512 with positioning ribs 1513 disposed at an inner annular rim of the positioning flange 1512. Adjacent positioning ribs 1513 define an air path 1514. The leakage-proof block is made from elastic material with a top end thereof fitted among the positioning ribs 1513 of the cap 151 and a bottom end having a taper 1521 for matching the internal taper 1311 of the detergent filler hole 131. In this manner, entry of air via the air vent 1511 of the cap 151 through the air path 1514 into the detergent receiving tank 13 may be controlled.
With further reference to FIGS. 4 and 5, when it is desired to eject a mixture of water and detergent via the nozzle 12, it is only necessary to put the control valve 92 of the lever 9 into a water intake mode and turn open the cap slightly to allow entry of air into the detergent receiving tank 13 via the air vent 1511 and the air channel formed among the positioning ribs 1513 and through a clearance defined between the taper 1521 at the bottom end of the leakage-proof block 152 and the internal taper 1311 at the top surface of the filler hole 131. The supply of air enables the suction port 142 of the detergent suction straw 14 to suck up detergent by siphon action with the adjustment of the cap 151 to control the intake of air and hence the amount of detergent released so that the detergent suction straw 14 may keep in contact with the detergent any time to allow release of detergent via the release hole 102 to mix with the water. Therefore, whatever angle the spray gun of the invention is held at in use, the spray gun may be controlled to eject water only or a mixture of water and detergent. If it is desired to use the spray gun of the invention to eject water, it is only necessary to keep the control valve of the lever 9 at a water intake state and tighten the cap 151 so that the taper 1521 of the leakage-proof block 152 and the internal taper 1311 of the filler hole 131 are in a sealingly closed state, blocking out entry of air into the detergent receiving tank 13 so that detergent cannot be released via the release hole 102.